1. Field of the Invention
The invention relates to a control apparatus and a control method for a vehicle driving unit which has a plurality of control elements and whose output torque is controlled in accordance with control amounts of the control elements.
2. Description of the Related Art
During acceleration of a vehicle, the vehicle may experience a shock when the torque output from a driving unit of the vehicle is excessively large. On the contrary, the occurrence of a shock can be prevented but a deterioration in acceleration response is caused when the outputting of the torque is excessively limited. As described hitherto, driveability is greatly affected by how to output a torque during acceleration. Therefore, various proposals have been made as to torque control of a vehicle. Arts regarding torque control of a vehicle are also disclosed in the following exemplary documents, namely, Japanese Patent Application Publication No. 2003-293812 (JP-A-2003-293812) and Japanese Patent Application Publication No. 9-323565 (JP-A-9-323565).
In the course of originating the invention, a new fact that the shock caused during acceleration of a vehicle changes depending on the operational state of a driving unit before acceleration has been ascertained. A case where the driving unit is an internal combustion engine will now be described. For example, it has been revealed that when a throttle is opened for acceleration, the ascending gradient of torque after the start of acceleration differs and the magnitude of a shock caused differs as well if the pressure in an intake pipe or the efficiency of filling the inside of each cylinder with air differs upon the opening of the throttle in spite of the same throttle opening degree.